1. Field of the Invention
The present invention relates to a switching mode power supply capable of varying charging and discharging currents according to a load, and a control method thereof.
2. Description of the Related Art
A switching mode power supply (SMPS) is an apparatus for rectifying and smoothing alternating current (AC) power and applying the rectified and smoothed power to a primary winding of a transformer, inducing the power applied to the primary winding to a secondary winding having a preset turns ratio between the primary winding and the secondary winding by a switching operation of a power switch, and then rectifying and smoothing the power induced to the secondary winding to obtain direct current (DC) power.
Generally, a power supply device such as a switching mode power supply, or the like, includes a power switch in order to convert power. In addition, such a power supply device includes a switching driving circuit generating a driving signal for driving the power switch.
Meanwhile, as a load connected to the switching mode power supply is increased, an instantaneous switching reaction of the power switch is required.
However, in the case in which the power switch is set to perform the instantaneous switching reaction, when the load is reduced, the switching mode power supply exhibits unstable output characteristics.
Therefore, there is a need to introduce a switching mode power supply having appropriate response characteristics to a load.
The following Related Art Document (Patent Document 1), which relates to a switching regulator suppressing overshooting of an output voltage in the case in which a load is rapidly decreased, does not disclose a configuration of regulating a switching current of a power switch according to an output load amount.